1. Field of the Invention
The present invention relates to optical networks and, more specifically, to cost reduction and restoration time improvement in mesh optical networks.
2. Description of the Related Art
Reliability and cost are two parameters that drive the design of modem day networks. To support high reliability, it is typical to provide path redundancy for services. To control costs, it is common to attempt to maximize the utilization of available resources and generate redundant paths in consideration of multiple-cost criteria.
Generally, reliability is supported by providing both a primary path and a restoration path for each service in the network. In the event of a failure along the primary path for a service, the service is switched over to the associated restoration path. For optical mesh networks, one challenge is to support restoration times that are comparable to those provided by SONET/SDH networks with self-healing rings (e.g., 10-100 ms restoration times). To help reduce network restoration time in optical mesh networks, a number of approaches have been considered, including improving restoration signaling and associated algorithms, and improving the switching speed of cross-connection infrastructure switching elements.